1. Field of the Invention
The present invention relates generally to processes for cleaning components using cleaning media, and more particularly to processes for cleaning semiconductor process components used in the manufacture of semiconductor devices, using cleaning media.
2. Description of the Related Art
In the art of semiconductor processing, various semiconductor processing components are used to handle semiconductor wafers during batch processing as well as during single wafer processing. Such components are also known in the art as xe2x80x98handling implementsxe2x80x99 or xe2x80x98work pieces,xe2x80x99 particular examples including quartz and silicon carbide wafer boats, paddles, carriers, and the like. As is understood in the art, semiconductor fabrication is a time-consuming and highly precise process, during which cleanliness of the working environment is of utmost importance. In this regard, semiconductor xe2x80x9cfabsxe2x80x9d include various classes of clean-rooms having purified air flows to reduce incidence of airborne particle contaminants.
As a part of the semiconductor fabrication process, wafers are exposed to high temperature environments, during which exposure various types of materials are deposited for formation of integrated circuits on the semiconductor die of the wafers. During such high temperature processes, layers such as silicon oxide (including TEOS, and thermally-grown oxide), polysilicon, silicon nitride, photoresist, and various metallic layers such as aluminum and copper are deposited. Invariably, such layers are also deposited on the wafer processing components utilized to handle the wafers.
With increased integration and density of semiconductor devices, and attendant shrinking of photolithographic patterns on the semiconductor die, it has become increasingly important to safeguard the cleanliness of the processing environment. In this regard, the materials deposited on the semiconductor processing components as noted above have been identified as a source of contamination during processing. Accordingly, various techniques have been employed in the art to clean semiconductor processing components after a predetermined number of cycles of use.
Cleaning of semiconductor processing components may be generally categorized into two major types, wet cleaning, which typically removes layers by dissolution (e.g., submersion into an acid solution to remove deposited layers), and dry cleaning, which primarily relies upon mechanical removal of deposited layers. While wet cleaning has been employed in the art and has been recognized as an effective means to remove unwanted materials on semiconductor processing components, wet processes suffer from numerous disadvantages. Particularly, the cycle time to effect material removal is lengthy, the cost of employing wet processes is relatively high, and technically sophisticated equipment is required to address out-gassing issues. In addition, wet cleaning methods typically trigger environmental health and safety concerns in view of the aggressive chemicals that are utilized to effect removal. Still further, in certain circumstances, it is difficult to control dissolution of the underlying substrate, such as dissolution of silicon (Si) in the case of silicon carbide (SiC) semiconductor processing components.
Dry cleaning processes address many of the disadvantages associated with wet processes. The advantages of dry processes over wet processes include reduced cycle time, elimination of out-gassing, low cost, and ease of implementation. Typically, dry cleaning processes involve flowing an alumina (Al2O3) or silicon carbide (SiC) abrasive material, akin to sand blasting. However, state of the art processes typically suffer from inefficient layer removal, or overly-aggressive layer removal, leading to damage of the underlying substrate, i.e., the semiconductor processing component. In severe cases, such damage can lead to chipping or breaking of the component. Certain processing components utilize a multi-phase structure, as in the case of silicon carbide semiconductor processing components coated with a silicon carbide layer formed by chemical vapor deposition (CVD). Component damage is particularly problematic with such multi-phase components.
Accordingly, a need exists in the art for improved cleaning processes, particularly, improved cleaning processes particularly suited for cleaning of semiconductor processing components having any one of or a combination of layers commonly deposited during state of the art semiconductor processing techniques.
In one aspect of present invention, a method for cleaning a semiconductor processing component is provided. The process calls for directing a stream of cleaning media at a surface of the component, the cleaning media including zirconia.
In another aspect of the present invention, a method for cleaning a component is provided. The process calls for directing a stream of cleaning media at a surface of the component, the cleaning media including zirconia, and directing a flow of frozen CO2 pellets against the surface of the component.